My 2002 750 Honda bike calls for 91 RON gas. What is RON? I have seen R+M/2. I have read that RON is always higher than Method, so can i use 87 octane or do i need to use 91? It is hard to hear pinging on a bike, since they are louder and have more noises that are hard to pin point.
What is RON?
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sinceyour scooter is a carbed model i would use only 87. when i first bought my scooter i ran the highest rated octane i could find. only later to find out i was increasing the amount of carbon build up. so i then ran seafoam in the tank and switched to low grade fuel and now all is great. btw my scooter is a 2002 kaw vn800B
http://www.cruisercustomizing.com/arkainzeye
http://www.cruisercustomizing.com/arkainzeye
RON is "research octane number".
MON is "motor octane number"
R+M/2 is the average of the two, and is what is normally posted on the pump.
MON is typically 10 points under RON in motor gasoline. Therefore, 87 octane as posted on the pump will usually satisfy 91 RON.
The differences between RON and MON is the nature of the octane test. The RON is run at a lower speed, and is a measure of the gasoline's resistance to knocking at start from rest conditions. MON is run at higher speeds, and is a measure of the gasoline's resistance to knocking at higher speeds, such as when you punch it to pass another vehicle, or to climb a hill under load.
In the distant past, oil companies would advertise the RON number, since it was higher than the MON number.
MON is "motor octane number"
R+M/2 is the average of the two, and is what is normally posted on the pump.
MON is typically 10 points under RON in motor gasoline. Therefore, 87 octane as posted on the pump will usually satisfy 91 RON.
The differences between RON and MON is the nature of the octane test. The RON is run at a lower speed, and is a measure of the gasoline's resistance to knocking at start from rest conditions. MON is run at higher speeds, and is a measure of the gasoline's resistance to knocking at higher speeds, such as when you punch it to pass another vehicle, or to climb a hill under load.
In the distant past, oil companies would advertise the RON number, since it was higher than the MON number.
"Because RON and MON are measured in a single-cylinder laboratory engine, they do not completely predict antiknock performance in multicylinder engines. There is a procedure to measure the antiknock performance of a gasoline in vehicles (see Chapter 3, Gasoline Refining and Testing). The resulting value is called Road octane number (RdON). Since vehicle testing is more involved than laboratory testing, there have been a number of attempts to predict RdON from RON and MON. The equations take the form:
RdON = a(RON) + b(MON) + c
"A good approximation for RdON sets a = b = 0.5 and c = 0, yielding (RON + MON)/2, commonly written (R + M)/2. This is called the Antiknock Index (AKI). The U.S. Federal Trade Commission requires dispensing pumps to be labeled (posted) with the gasoline's AKI.1
Footnotes
1 The gasoline being dispensed must have an antiknock index equal to or greater than the posted value. Rounding the number upward is not permitted. Owner's manuals in the U.S. also must indicate the octane number recommendation for vehicles2
Footnotes
2 Older owner's manuals of some foreign cars specify RON; some more recent ones specify both RON and AKI. by AKI. (R + M)/2 is voluntarily posted in Canada.
"Neither the AKI nor the several other single-value indices that have been developed work for all vehicles. The performance of some vehicles correlates better with RON or MON alone than with a combination of the two. And for a given vehicle, the correlation can vary with driving conditions. (See Chapter 1, Figure 1-5 for the variables that affect an engine’s octane requirement.)
"As the formula indicates, gasolines with the same AKI can have different RONs and MONs. This may explain why a vehicle knocks with some fill-ups of the same brand but not with others; or why it knocks with one brand of gasoline but not with another. Of course, for a comparison to be valid, the vehicle must be operated under identical conditions, which is not easy for the typical driver." http://www.chevron.com/prodserv/fuels/bulletin/motorgas/1_driving-performance/pg3.asp
Ken
[ July 01, 2004, 07:00 PM: Message edited by: Ken2 ]
RdON = a(RON) + b(MON) + c
"A good approximation for RdON sets a = b = 0.5 and c = 0, yielding (RON + MON)/2, commonly written (R + M)/2. This is called the Antiknock Index (AKI). The U.S. Federal Trade Commission requires dispensing pumps to be labeled (posted) with the gasoline's AKI.1
Footnotes
1 The gasoline being dispensed must have an antiknock index equal to or greater than the posted value. Rounding the number upward is not permitted. Owner's manuals in the U.S. also must indicate the octane number recommendation for vehicles2
Footnotes
2 Older owner's manuals of some foreign cars specify RON; some more recent ones specify both RON and AKI. by AKI. (R + M)/2 is voluntarily posted in Canada.
"Neither the AKI nor the several other single-value indices that have been developed work for all vehicles. The performance of some vehicles correlates better with RON or MON alone than with a combination of the two. And for a given vehicle, the correlation can vary with driving conditions. (See Chapter 1, Figure 1-5 for the variables that affect an engine’s octane requirement.)
"As the formula indicates, gasolines with the same AKI can have different RONs and MONs. This may explain why a vehicle knocks with some fill-ups of the same brand but not with others; or why it knocks with one brand of gasoline but not with another. Of course, for a comparison to be valid, the vehicle must be operated under identical conditions, which is not easy for the typical driver." http://www.chevron.com/prodserv/fuels/bulletin/motorgas/1_driving-performance/pg3.asp
Ken
[ July 01, 2004, 07:00 PM: Message edited by: Ken2 ]
In my '86 Yamaha FZ600, I'd lots of times run 110 octane leaded race gas, just for the smell. It always seemed to run better on it than on 93. Much smoother and felt a ton stronger on the top end.
Since I was getting 50 MPG when I drove it nice, the cost of the race gas wasn't all that important.
That bike did call for premium unleaded.
What grade of gasoline would you recommend in a '80 Honda CB750? Also, how do bike engines react to a 10% ethanol blend compared to straight gasoline? This particular one seems to run a tad lean as it is...Would the ethanol cause it to run leaner still?
Since I was getting 50 MPG when I drove it nice, the cost of the race gas wasn't all that important.
That bike did call for premium unleaded.
What grade of gasoline would you recommend in a '80 Honda CB750? Also, how do bike engines react to a 10% ethanol blend compared to straight gasoline? This particular one seems to run a tad lean as it is...Would the ethanol cause it to run leaner still?
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